1. Field of the Invention
The present invention relates in general to multi-media writing instruments and to methods for the manufacture and use of such writing instruments. More particularly, the present invention is directed to multi-media writing instruments having an integrated indicator grip.
2. General Background and State of the Art
Writing instruments vary in price, type, and features through technological advancements in material chemistry and improved manufacturing techniques. Given these advancements, writing instruments range from mass-produced plastic pens to fine writing instruments. The wide range of writing instruments vary in characteristics such as materials used, design, features, asethetics, perceived quality, details, utility, prestige, reputation, etc. Further adding to the differentiation amongst various writing instruments is the media used. That is, information may be conveyed by using ink, lead, paint, etc. Today, with the advent of personal data assistants, styluses are also used to input information.
Given the wide variety of writing instruments that an individual may use, multi-media writing instruments were developed. These writing instruments allowed the user to have one writing instrument that could alternate between different writing elements. A user could switch between different ink colors or switch between ink and pencil lead without having to switch to different writing instruments. This is more efficient to various users because the user does not have to carry a large number of writing instruments or alternate between various types of writing instruments. A user can simply carry and use a single writing instrument having different writing media elements.
Another feature that distinguishes writing instruments are features that make the writing instrument more comfortable to use. Various enhancements have improved the comfort level of writing instruments. The shape and size of writing instrument has been altered to provide a more comfortable writing position. For instance, various writing instruments have a larger diameter near the writing tip so that the user does not have to hold the device so tightly, thereby emulating a more natural hand position. Writing implements have changed in the materials used to form the shaft of the writing instrument. For instance, rubber and other like materials that provide more cushioning and better tactile feel. Additionally, there are after-market grips that slide onto various writing instruments that provide better hand ergonomics, cushioning, and overall comfort.
However, there have been many problems with the use of rubber grips. The rubber used to make the grips have different levels of shore hardness. Sure hardness is a measure of the softness of a particular compound. Generally, manufacturer want the grips to made from rubber with lower hardness levels, that is softer rubber. However, rubber with low sure hardness values tend to swell in response to extended contact with naturally-occurring body oils and elevated temperatures. This causes the rubber to grow in size which compromises the fit and finish of the rubber grip. That is, the rubber grip can rotate around the pen body or slide up and down the pen body. A solution has been to use rubber with higher sure hardness levels, but this tends to reduce the comfort level of the grip.
Writing instruments having multiple writing media elements have different means of switching between the different types of writing media. For instance, a writing instrument can switch between two different media by pushing a button or switching a lever. In particular applications, a portion of the pen housing will rotate relative to another portion of the pen housing wherein the rotation will cause the writing media to change. Usually, when the writing media is changed, there needs to be a way to discern between the different media being used. It is very difficult to discern what writing element you are using by just examining the writing instrument tip. There have been many designs where the writing instruments has various indicators and markings etched on the pen housing wherein when the pen is rotated the user is notified of what writing element is being used. There is a problem, however, when using a rubber grip and a rotating multi-media pen. When the grip swells, the indicator may incorrectly tell the user that they are using a particular media. This is particularly important when the pen contains different colors of ink. Additionally, this is important where a metal tip found on a mechanical pencil or pen may damage the screen of a personal data assistant.
Moderate improvements have been made when addressing the problem of using a multi-media pen and employing rubber grips. In particular, the indicator is painted on to the pen grip or stamped on to the pen grip, but there have been problems with quality and aesthetics. One solution has been co-molding an indicator with the grip, however, this is a very expensive manufacturing process, which requires expensive machinery. Additionally, time and complexity of manufacturing can not be justified for the retail price of the product. It is not economically feasible to produce such a product. Consequently, cost reduction and improved quality are continued goals when designing any writing instrument. Therefore, there exists a need to provide an improved writing instrument meeting predetermined requirements while meeting or exceeding current efficiencies in cost and production, while maintaining high fit and finish.
It is an object of the present invention to provide non-rotating upper and lower grips for a multi-media writing instruments.
It is another object of the present invention to provide a grip having an integrated indicator grip.
It is yet another object of the present invention to provide a multi-media writing instrument that is inexpensive to manufacture, easy to use, and is cost effective.
The present invention seeks to produce a multi-media writing instrument with a high quality fit and finish. Specifically, the present invention achieves this goal by having upper and lower grips that are locked into position. More particularly, the upper grip has an indicator which is also responsible for locking the grip into position. In achieving a higher fit and finish, the design of the present invention provides maintains a competitive cost and efficient manufacturing process.
The multi-media writing instrument comprises a first housing (distal housing) and a second housing (proximal housing). The second housing of the multi-media writing instrument is rotatively coupled to the first housing. A first grip is secured to the first housing by locking members that extend along the interior of the first grip. The first housing contains channels wherein these channels correspond to the location and size of the locking members of the first grip. The second housing includes a second grip that is locked into position. That is, the second grip will not slide or rotate around the axis of the second housing. The second grip of the present invention also includes an aperture that receives a locking member from an indicator sleeve. The locking member of this particular embodiment acts as both a locking member forte grip and as an indicator communicating the user the particular media that is selected.
Using a combination locking member improves the fit and finish of the writing instrument. First, the grip is locked into place with the locking member. This prevents the grip from sliding out of position or rotating about the outer diameter of the writing instrument. Next, it also provides greater aesthetics. A large plastic indicator clearly indicates the selected writing element. This results in consistent manufacturing quality at lower costs. On the other hand, painting an indicator or stamping an indicator in the aperture of the grip leads to varied quality and more expensive machinery.
To form the integrated indicator grip, an indicator sleeve (base sleeve) having a locking member is scoured to the housing of the writing instrument. A grip (gripping sleeve) having an aperture is then slipped over the indicator sleeve. Once in position, the locking member of the indicator sleeve protrudes through the aperture of the grip, thereby locking the grip into position. This process yields a product with high fit and finish while providing an efficient and inexpensive manufacturing process. The grip can be easily manufactured by simply sliding different elements over each other and having various lugs or other locking members to affix the yip in to proper position.